1984 Volume 75 Issue 2 Pages 211-214
A Bleomycin/Concanavalin-A conjugate (BLM/Con A) was prepared for the purpose of enhancing activity of Bleomycin. The extent of substitution was approximately 8 moles BLM per a mole Con A. Fifty percent inhibiting concentrations of the conjugate (IC50) against cultured HeLa cells were 40μg/ml at the continuous treatment (72hrs. treatment) and 10.6μg/ml at the short time exposure (1hr. treat-ment). The IC50 values as BLM corrected from the weight ratio of the conjugate were 0.432μg/ml at the continuous treamtment and 1.14μg/ml at the short time exposure, whereas the IC50, when HeLa cells were treated by BLM alone, were 1.9μg/ml at the former condition and 20.0μg/ml at the latter condition. Con A itself did not inhibit the growth of HeLa cells at the concentration of up to 10μg/ml. Twenty mg/ml of α-methyl-D-mannoside, specific inhibitor of Con A, prevented the growth inhibiting activity of the conjugate.
BLM/Con A conjugate was tested for a possibility as an intravesical chemotherapeutic agent against an experimental bladder tumor that was made by tumor cell (MBT-2) implantation to the fulgulated mouse (C3HIHe) bladder mucosa.
The results indicated that BLM/Con A conjugate might be useful as an intravesical chemotherapeutic agent against a bladder tumor. Further experiments are now undergoing.
